Answer:
c) 6s
Explanation: take downwards as positive.
let vf = the velocity of the stone when it hits the ground, vi = 0 be the starting velocity of the stone. r0 = 175m be the height of the building.
(vf)^2 = (vi)^2 + 2g(r-r0)
(vf)^2 = 2g(r0)
vf = \sqrt{2g(r0)}
= \sqrt{2×9.8×(175)}
= 58.6 m/s
then:
vf = vi + g×t
vf = g×t
t = vf/g
= (58.6)/(9.8)
= 6s
Therefore, it will take the stone 6 seconds to reach the gound.
Physics
What is the momentum of a 1.5 × 103 kilogram van that is moving at a velocity of 32 meters/second? A. 46.9 kilogram meters/second B. 4.7 × 103 kilogram meters/second C. 4.85 × 102 kilogram meters/second D. 4.85 × 104 kilogram meters/second
Answer:
1.056 x 10⁷ lb-ft
Explanation:
v = Speed of the bike = 20 mph
t = time of travel = 2 h
d = distance traveled by cyclist
Distance traveled by cyclist is given as
d = v t
d = (20) (2)
d = 40 miles
We know that, 1 mile = 5280 ft
d = 40 (5280) ft
d = 211200 ft
F = force applied by cyclist = 50 lb
W = work done by cyclist
Work done by cyclist is given as
W = F d
W = (50) (211200)
W = 1.056 x 10⁷ lb-ft
Answer:
40.13491 m/s
Explanation:
= My speed = 35 m/s
v = Speed of sound in air = 343 Hz
= Speed of the police car
When the car is approaching
When the car is receding
Dividing the equations
The speed of the police car is 40.13491 m/s
